August 22, 2014
Busting myths about ticks
A walk through the woods, a fishing trip, or an evening playing in the yard with your children are situations with the potential to encounter dozens, even hundreds of blood-sucking pests known as ticks. Ticks can be a problem year-round, but they pose the most threat in warmer summer months. These disease carriers could be harmful to humans and pets alike.
Michael Dryden, is a university distinguished professor of diagnostic medicine and pathobiology at Kansas State University's College of Veterinary Medicine and one of the world's leading experts on ticks. He said when thinking about sheer tick numbers, Kansas is considered "tick central," especially the eastern and southeastern regions. People should know and understand the common myths associated with ticks to protect themselves, their children and their pets.
Myth No. 1: A tick is an insect.
A tick is not an insect, Dryden said, but rather, an arachnid.
"A spider is an arachnid, so a tick is closely related to a spider," he said. "What's the difference? Basically, insect adults have six legs, and arachnids as adults have eight legs. They're both arthropods, but there's a difference."
Worldwide, there are 400-450 species of ticks, and about 90 of those species live in North America, Dryden said. Most ticks in Kansas and surrounding states are generalists, which means they aren't host-specific.
In eastern Kansas, the lone star tick is probably the most common species, he said, and it's not host-specific. Many people recognize the females, because they have a white dot on their back. This is how the species got its name.
The lone star tick isn't as common west of Salina, Dryden said, because the tick needs adequate moisture and tree cover to survive.
Could it be the spider-like resemblance that causes people to fear ticks, or is it more that people fear tick-transmitted diseases? Dryden said it's probably a little of both. He also researches fleas, another pest that people don't seem to worry about as much as ticks. The fear of ticks could come from an awareness of diseases ticks transmit.
"Fleas are bad," he said. "They're blood-sucking parasites as well. They certainly can cause a lot of damage and harm, and kill animals. But, a lot of people tend to put up with fleas to one extent or another. You get a few ticks on an animal, people seem to be more concerned."
Myth No. 2: Ticks jump out of trees to land on their hosts.
Many people believe ticks jump out of trees and land on them, but it turns out they are physically unable to do that.
"I always say 'Don't ruin a good story with the truth,' but they're not raining out of trees on us," Dryden said.
Ticks undergo questing — an ambush strategy — to find their next victim. When questing, they crawl up low shrubs, bushes or blades of grass, for example, anchor themselves with the hind legs, reach their front legs out in front of them and wave those legs in the air to detect a host.
"Those front legs contain Haller's organs, which are heat and carbon dioxide receptors," he said. "They wave them around in the air and try to detect an animal or human going by. As you brush up against them, they grab on."
"They can't leap. They can't jump. They have no physical mechanism to do that. There's no evidence that ticks climb way up into trees," he added. "Some of these ticks, like the ones that transmit Lyme disease, have no photo receptors. They can't see. They live their entire life in the dark."
Most ticks like shaded areas, such as tree canopies, Dryden said. The lone star tick is one species that needs a deciduous forest canopy to survive hot summers and cold winters. Tick numbers increase dramatically under the tree canopy. Also, large whitetail deer populations tend to drive high numbers of ticks to a specific area.
"The ticks get on you, and they often crawl up the back of your pants and shirts," he said. "The first piece of bare skin they hit is right on the back of the neck. We reach around, feel them and look up. The reaction and why we think they fall from trees is perfectly normal."
Myth No. 3: Apply heat to a tick to get it to come out.
Applying heat to a tick to get it to release from the skin is a bad idea and could make the host more susceptible to getting a tick-transmitted disease, Dryden said. The first thing to do is pull it off. Using tweezers can help, but if none are available, people should grab the tick as close to the skin as possible and pull it straight off without twisting or irritating it.
"Most people don't understand that these ticks generally transmit the pathogens — viruses, bacteria, protozoa — to us in their saliva," he said. "If you irritate the tick with a match, Vaseline, whatever it may be, one of the first things the tick does when it's irritated is it salivates more. It starts regurgitating. If it hasn't passed a pathogen to you yet, now you've basically ensured that it's going to."
Generally, getting the ticks off within 24 to 48 hours dramatically reduces the risk of obtaining a tick-transmitted disease, Dryden said. Some diseases could be transmitted earlier than 24 hours under some circumstances, but the odds are in the host's favor if the tick comes off within a day.
Myth No. 4: The tick's head must come out.
"It's really not a head per se," Dryden said. "It's the anterior end and just the mouthparts. There's no evidence that's a problem if left in the skin."
The worse thing that will happen if parts of the tick are left in this skin is the person or pet might have a small welt, almost like a chigger bite, he said. But, a welt will likely show up even if the entire tick comes out, particularly with the lone star tick. The welt is just an inflammatory response from the tick's salivary proteins.
Myth No. 5: All animal tick repellants work the same.
Ticks in numbers have the potential to get on animals and kill them from exsanguination, let alone all the diseases they might transmit to the animals, Dryden said. He's seen dogs with 500 to 1,000 ticks on them.
Dryden said people should talk to their veterinarian about what is the most effective tick product for their particular pet. Not every product works the same everywhere, because different ticks respond differently to different compounds.
Also, new products are always coming down the pipeline to keep ticks away from pets, and veterinarians will hopefully be up-to-date on what's happening with new products and can tell pet owners about them, he said.
"Some of these new products are prescription-only, so you can only get them from your vet," Dryden said. "You need to make sure your animals will tolerate these products well."
Dryden said he believes dogs and cats in Kansas should be on a product year-round and never taken off, as ticks can be a problem throughout the year.
"This last winter was hard, and we didn't start seeing ticks until March," he said. "But, in years past we've seen ticks in January."
Myth No. 6: Applying repellants and spraying the yard won't do any good.
Dryden said due to the length and below average temperatures of last winter, ticks don't seem to present as much of a problem this summer compared to recent years.
"A long winter tends to slow tick numbers," he said. "That's going to change year-to-year. But, there's been a general upward trend for the last 25 years. They seem to be getting worse over time in numbers, densities and diseases."
Dryden added that even if tick numbers are low overall, certain areas could see staggering numbers of the pests. Local climatic conditions including temperature, humidity and snow cover as examples, can affect seasonal, even month-to-month tick populations. People should take precautions to limit their exposure to ticks.
"For human protection, there are a few things we can do," Dryden said. "There are some common insect repellants out there. I'm a fan of DEET. It's an effective repellant and does a good job protecting us from ticks, but nothing is perfect."
He said don't put too much repellant on the skin of children and that it might be better to put it on their clothes. An alternative to repellant is to impregnate clothing with a compound called permethrin, which can be found at many sporting goods stores. People shouldn't get permethrin on their skin and need to let their clothes dry before wearing.
In using both repellant and permethrin, it's important to follow the label directions, Dryden said.
For yards, using a spray that contains a compound called cyfluthrin can be effective for tick control.
"You're generally going to spray under the shrubs, bushes and around the edge of your property," Dryden said. "It's critical of any insecticide to always follow the label recommendations provided by the EPA and the manufacturer of that product. Spray the product, and let it dry before you let the pets and kids have access to that area."
An alternative to personally spraying the yard is to hire a professional exterminator, he said.